The Prisma Vision deck is super dark. I swear every card looks like it’s been dipped in shadows. Kind of creepy but the artwork is good. Not for everyone though.
Since he’s deep into shadow work, you could tuck in some black tourmaline or obsidian with the deck. That kind of imagery can stir a lot up. A grounding stone on hand can make it feel less overwhelming.
Just so you know, those spooky indies like Carnival at the End of the World and Bohemian Gothic go in and out of stock a lot. Sometimes you wait months for a reprint. The secondhand market takes patience maybe 2-6 weeks of looking. I’d set up alerts now if you need it by a certain date.
Check out Aecliectic, they have deck lists that cover pretty much everything. Their catalog is huge so you’ll probably find what you’re looking for.